SYSTEM AND METHOD FOR DELIVERING AND DEPLOYING AN OCCLUDING DEVICE WITHIN A VESSEL
A system and method for deploying an occluding device that can be used to remodel an aneurysm within the vessel by, for example, neck reconstruction or balloon remodeling. The system comprises an introducer sheath and an assembly for carrying the occluding device. The assembly includes an elongated flexible member having an occluding device retaining member for receiving a first end of the occluding device, a proximally positioned retaining member for engaging a second end of the occluding device and a support surrounding a portion of the elongated flexible member over which the occluding device can be positioned.
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This application is a continuation of U.S. application Ser. No. 11/136,398, filed May 25, 2005, which is expressly incorporated herein by reference in its entirety.
FIELD OF THE INVENTIONThe invention generally relates to a system and method for delivering and deploying a medical device within a vessel, more particularly, it relates to a system and method for delivering and deploying an endoluminal therapeutic device within the vasculature of a patient to embolize and occlude aneurysms, particularly cerebral aneurysms.
BACKGROUND ART OF THE INVENTIONWalls of the vasculature, particularly arterial walls, may develop areas of pathological dilatation called aneurysms. As is well known, aneurysms have thin, weak walls that are prone to rupturing. Aneurysms can be the result of the vessel wall being weakened by disease, injury or a congenital abnormality. Aneurysms could be found in different parts of the body with the most common being abdominal aortic aneurysms and brain or cerebral aneurysms in the neurovasculature. When the weakened wall of an aneurysm ruptures, it can result in death, especially if it is a cerebral aneurysm that ruptures.
Aneurysms are generally treated by excluding the weakened part of the vessel from the arterial circulation. For treating a cerebral aneurysm, such reinforcement is done in many ways including: (i) surgical clipping, where a metal clip is secured around the base of the aneurysm; (ii) packing the aneurysm with small, flexible wire coils (micro-coils); (iii) using embolic materials to “fill” an aneurysm; (iv) using detachable balloons or coils to occlude the parent vessel that supplies the aneurysm; and (v) intravascular stenting.
Intravascular stents are well known in the medical arts for the treatment of vascular stenoses or aneurysms. Stents are prostheses that expand radially or otherwise within a vessel or lumen to provide support against the collapse of the vessel. Methods for delivering these intravascular stents are also well known.
In conventional methods of introducing a compressed stent into a vessel and positioning it within in an area of stenosis or an aneurysm, a guiding catheter having a distal tip is percutaneously introduced into the vascular system of a patient. The guiding catheter is advanced within the vessel until its distal tip is proximate the stenosis or aneurysm. A guidewire positioned within an inner lumen of a second, inner catheter and the inner catheter are advanced through the distal end of the guiding catheter. The guidewire is then advanced out of the distal end of the guiding catheter into the vessel until the distal portion of the guidewire carrying the compressed stent is positioned at the point of the lesion within the vessel. Once the compressed stent is located at the lesion, the stent may be released and expanded so that it supports the vessel.
SUMMARY OF THE INVENTIONAspects of the present invention include a system and method of deploying an occluding device within a vessel. The occluding device can be used to remodel an aneurysm within the vessel by, for example, neck reconstruction or balloon remodeling. The occluding device can be used to form a barrier that retains occlusion material such as a well known coil or viscous fluids, such as “ONYX” by Microtherapeutics, within the aneurysm so that introduced material will not escape from within the aneurysm. Also, during deployment, the length of the occluding device can be adjusted in response to friction created between the occluding device and an inner surface of a catheter. When this occurs, the deployed length and circumferential size of the occluding device can be changed as desired by the physician performing the procedure.
An aspect of the present invention includes a system for supporting and deploying an occluding device. The system comprises an introducer sheath and an assembly for carrying the occluding device. The assembly includes an elongated flexible member having an occluding device retaining member for receiving a first end of the occluding device, a proximally positioned retaining member for engaging a second end of the occluding device and a support surrounding a portion of the elongated flexible member over which the occluding device can be positioned.
Another aspect of the present invention includes a system for supporting and deploying an occluding device. The system comprises an assembly for carrying the occluding device. The assembly comprises an elongated member including a flexible distal tip portion, a retaining member for receiving a first end of the occluding device, and a support surrounding a portion of the elongated flexible member for supporting the occluding device.
A further aspect of the present invention comprises a method of introducing and deploying an occluding device within a vessel. The method includes the steps of introducing an elongated sheath including an introducer sheath carrying a guidewire assembly into a catheter and advancing the guidewire assembly out of the sheath and into the catheter. The method also includes the steps of positioning an end of the catheter proximate an aneurysm, advancing a portion of the guidewire assembly out of the catheter and rotating a portion of the guidewire assembly while deploying the occluding device in the area of the aneurysm.
An occluding device delivery assembly having portions with small cross section(s) and which is highly flexible is described herein.
A distal end 12 of the introducer sheath 10 is sized and configured to be received within a hub 2 of the micro-catheter 1, as shown in
The micro-catheter 1 may have at least one fluid introduction port 6 located adjacent the hub 2 or at another position along its length. The port 6 is preferably in fluid communication with the distal end of the micro-catheter 1 so that a fluid, e.g., saline, may be passed through the micro-catheter 1 prior to insertion into the vasculature for flushing out air or debris trapped within the micro-catheter 1 and any instruments, such as guidewires, positioned within the micro-catheter 1. The port 6 may also be used to deliver drugs or fluids within the vasculature as desired.
The introducer sheath 10 may include drainage ports or purge holes (not shown) formed into the wall near the area covering the occluding device 100. There may be a single hole or multiple holes, e.g., three holes, formed into introducer sheath 10. These purge holes allow for fluids, e.g., saline, to readily escape from in between the introducer sheath 10 and the guidewire assembly 20 when purging the sheath prior to positioning the introducer sheath 10 in contact with the catheter hub 2, e.g., to remove trapped air or debris.
As shown in
The guidewire assembly 20 can have the same degree of flexion along its entire length. In an alternative embodiment, the guidewire assembly 20 can have longitudinal sections, each with differing degrees of flexion/stiffness. The different degrees of flexions for the guidewire assembly 20 can be created using different materials and/or thicknesses within different longitudinal sections of the guidewire 21. In another embodiment, the flexion of the guidewire 21 can be controlled by spaced cuts (not shown) formed within the delivery guidewire 21. These cuts can be longitudinally and/or circumferentially spaced from each other. The cuts can be formed with precision within the delivery guidewire 21. Different sections of the delivery guidewire 21 can include cuts formed with different spacing and different depths to provide these distinct sections with different amounts of flexion and stiffness. In any of the above embodiments, the guidewire assembly 20 and the guidewire 21 are responsive to torque applied to the guidewire assembly 20 by the operator. As discussed below, the torque applied to the guidewire assembly 20 via the guidewire 21 can be used to release the occluding device 100 from the guidewire assembly 20.
The size and shape of the cuts formed within the delivery guidewire 21 may be controlled so as to provide greater or lesser amounts of flexibility. Because the cuts can be varied in width without changing the depth or overall shape of the cut, the flexibility of the delivery guidewire 21 may be selectively altered without affecting the torsional strength of the delivery guidewire 21. Thus, the flexibility and torsional strength of the delivery guidewire 21 may be selectively and independently altered.
Advantageously, longitudinally adjacent pairs of cuts may be rotated about 90 degrees around the circumference of the delivery guidewire 21 from one another to provide flexure laterally and vertically. However, the cuts may be located at predetermined locations to provide preferential flexure in one or more desired directions. Of course, the cuts could be randomly formed to allow bending (flexion) equally, non-preferentially in all directions or planes. In one embodiment, this could be achieved by circumferentially spacing the cuts.
The flexible delivery guidewire 21 can include any number of sections having the same or differing degrees of flexion. For example, the flexible delivery guidewire 21 could include two or more sections. In the embodiment illustrated in
The second, transition section 24 extends between the first section 22 and a third, distal section 26. The second section 24 tapers in thickness from the large diameter of the first section 22 to the smaller diameter of the third section 26. As with the first section 22, the second section 24 can taper along its entire length or only a portion of its length.
The third section 26 has a smaller thickness compared to the other sections 22, 24 of the delivery guidewire 21. The third section 26 extends, away from the tapered second section 24 that carries the occluding device 100. The third section 26 can taper along its entire length from the second section 24 to the distal end 27 of the delivery guidewire 21. Alternatively, the third section 26 can have a constant diameter or taper along only a portion of its length. In such an embodiment, the tapering portion of the third section 26 can extend from the second section 24 or a point spaced from the second section 24 to a point spaced from distal end 27 of the delivery guidewire 21. Although three sections of the delivery guidewire 21 are discussed and illustrated, the delivery guidewire 21 can include more than three sections. Additionally, each of these sections can taper in their thickness (diameter) along all or only a portion of their length. In any of the disclosed embodiments, the delivery guidewire 21 can be formed of a shape memory alloy such as Nitinol.
A tip 28 and flexible tip coil 29 are secured to the distal end 27 of the delivery guidewire 21 as shown in
As shown in
The tip 28 and coil 29 have an outer diameter D1 of about 0.010 inch to about 0.018 inch. In an embodiment, their outer diameter D1 is about 0.014 inch. The tip 28 and coil 29 also have a length L1 of about 0.1 cm to about 3.0 cm. In an embodiment, they have a total length L1 of about 1.5 cm.
A proximal end 30 of the tip coil 29 is received within a housing 32 at a distal end 24 of a protective coil 35, as shown in
The housing 32 has a non-percutaneous, atraumatic shape. For example, as shown in
The housing 32 and protective coil 35 form a distal retaining member that maintains the position of the occluding device 100 on the flexible guidewire assembly 20 and helps to hold the occluding device 100 in a compressed state prior to its delivery and deployment within a vessel of the vasculature. The protective coil 35 extends from the housing 32 in the direction of the proximal end 23 of the delivery guidewire 21, as shown in
At the proximal end of the occluding device 100, a bumper coil 60 and cap 62 prevent lateral movement of the occluding device 100 along the length of the guidewire 21 in the direction of the proximal end 23, see
In an alternative embodiment illustrated in
In an alternative embodiment, the bumper coil 60 and cap 62 can be eliminated and the proximal end of the occluding device 100 can be held in position relative to the protective coil 35 by a tapered section of the guidewire 21. In such an embodiment, the enlarged cross section of this tapered section can be used to retain the occluding device 100 in position along the length of the delivery guidewire 21 and prevent movement of the occluding device 100 in the direction of the proximal end 23.
As shown in
The mid-coil 70 provides the guidewire assembly 20 with an outwardly extending surface that is sized to contact the inner surface of the occluding device 100 in order to assist in supporting the occluding device and maintaining the occluding device 100 in a ready to deploy state. Like the other coils discussed herein and illustrated in the figures, the coiled form of the mid-coil 70 permits the mid-coil 70 to flex with the delivery guidewire 21 as the delivery guidewire 21 is advanced through the vasculature of the patient. The mid-coil 70 provides a constant diameter along a length of the delivery guidewire 21 that is covered by the occluding device 100 regardless of the taper of the delivery guidewire 21 beneath the occluding device 100. The mid-coil 70 permits the delivery guidewire 21 to be tapered so it can achieve the needed flexibility to follow the path of the vasculature without compromising the support provided to the occluding device 100. The mid-coil 70 provides the occluding device 100 with constant support regardless of the taper of the delivery guidewire 21 prior to the occluding device 100 being deployed. The smallest diameter of the occluding device 100 when in its compressed state is also controlled by the size of the mid-coil 70. Additionally, the diameter of the mid-coil 70 can be chosen so that the proper spacing, including no spacing, is established between the occluding device 100 and the inner wall of the micro-catheter 1 prior to deployment of the occluding device 100. The mid-coil 70 can also be used to bias the occluding device 100 away from the delivery guidewire 21 during its deployment.
In either embodiment, the support 70 can have an outer diameter D3 of about 0.010 inch to about 0.018 inch. In an embodiment, the outer diameter D3 is about 0.014 inch. The support 70 can also have a length L3 of about 2.0 cm to about 30 cm. In an embodiment, the length L3 of the support 70 is about 7 cm.
The occluding device 100 may also be placed on the mid-coil 70 between an optional pair of radio-opaque marker bands located along the length of the guidewire assembly 20. Alternatively, the protective coil 35, bumper coil 60 and or mid-coil 70 can include radio-opaque markers. In an alternative embodiment, the guidewire assembly 20 may include only a single radio-opaque marker. The use of radio-opaque markers allows for the visualization of the guidewire assembly 20 and the occluding device 100 during placement within the vasculature. Such visualization techniques may include conventional methods such as fluoroscopy, radiography, ultra-sonography, magnetic resonance imaging, etc.
The occluding device 100 can be delivered and deployed at the site of an aneurysm A according to the following method and variations thereof. The delivery of the occluding device 100 includes introducing the micro-catheter 1 into the vasculature until it reaches a site that requires treatment. The micro-catheter 1 is introduced into the vasculature using a conventional technique such as being advanced over or simultaneously with a conventional vascular guidewire (not shown). The positioning of the micro-catheter 1 can occur before it receives the guidewire assembly 20 or while it contains the guidewire assembly 20. The position of the micro-catheter 1 within the vasculature can be determined by identifying radio-opaque markers positioned on or in the micro-catheter 1.
After the micro-catheter 1 is positioned at the desired location, the guidewire is removed and the distal end of the introducer sheath 10 is inserted into the proximal end of the micro-catheter 1, as shown in
The guidewire assembly 20 and the occluding device 100 are advanced through the micro-catheter 1 until the tip coil 29 is proximate the distal end of the micro-catheter 1. At this point, the position of the micro-catheter 1 and guidewire assembly 20 can be confirmed. The guidewire assembly 20 is then advanced out of the micro-catheter 1 and into the vasculature of the patient so that the proximal end 107 of the occluding device 100 is positioned outside the distal end of the micro-catheter 1 and adjacent the area to be treated. At any point during these steps, the position of the occluding device 100 can be checked to determine that it will be deployed correctly and at the desired location. This can be accomplished by using the radio-opaque markers discussed above.
When the distal end 102 of the occluding device 100 is positioned outside the micro-catheter 1, the proximal end 107 will begin to expand, in the direction of the arrows shown in
In an alternative or additional deployment step shown in
After the occluding device 100 radially self-expands into gentle, but secure, contact with the walls of the vessel so as to occlude the neck of the aneurysm A, the micro-catheter 1 may be removed entirely from the body of the patient. Alternatively, the micro-catheter 1 may be left in position within vasculature to allow for the insertion of additional tools or the application of drugs near the treatment site.
Known materials can be used in the present invention. One common material that can be used with the occluding device 100 and the guidewire 21 is Nitinol, a nickel-titanium shape memory alloy, which can be formed and annealed, deformed at a low temperature, and recalled to its original shape with heating, such as when deployed at body temperature in the body. The radio-opaque markers can be formed of radio-opaque materials including metals, such as platinum, or doped plastics including bismuth or tungsten to aid in visualization.
The apparatus and methods discussed herein are not limited to the deployment and use within the vascular system but may include any number of further treatment applications. Other treatment sites may include areas or regions of the body such as organ bodies. Modification of each of the above-described apparatus and methods for carrying out the invention, and variations of aspects of the invention that are obvious to those of skill in the art are intended to be within the scope of the claims. Furthermore, no element, component or method step is intended to be dedicated to the public regardless of whether the element, component or method step is explicitly recited in the claims.
Claims
1-35. (canceled)
36. A system for supporting and deploying a self-expanding device, said system comprising:
- a self-expanding device;
- an introducer sheath; and
- an assembly for carrying the self-expanding device, said assembly comprising: (a) an elongate flexible member; (b) a device retaining member comprising a protective coil receiving a first end of the self-expanding device into a proximalmost opening of, and concentrically within, an interior portion of the protective coil; and (c) a proximally positioned retaining member for engaging a second end of the self-expanding device; said flexible member forming a support extending between the device retaining member and the proximally positioned retaining member and having an outer surface for engaging an inner surface of said self-expanding device, the protective coil being rotatable relative to the self-expanding device;
- wherein rotation of the protective coil results in disengagement of the first end from within the interior portion, said self-expanding device being movable relative to said flexible member;
- wherein said proximally positioned retaining member includes a stopper that urges the self-expanding device toward a distal end of the flexible member when the self-expanding device is positioned on said flexible member and against said stopper.
37. The system according to claim 36, wherein said elongate flexible member includes a guidewire having a flexible atraumatic tip.
38. The system according to claim 37, wherein said guidewire is movable relative to said introducer sheath.
39. The system according to claim 38, wherein said guidewire has at least two sections having different diameters.
40. The system according to claim 38, wherein said guidewire has sections of differing flexions.
41. The system according to claim 36, wherein said flexible member surrounds a portion of said elongate flexible member.
42. The system according to claim 36, wherein said proximally positioned retaining member is a portion of said elongate flexible member.
43. The system according to claim 36, wherein said device retaining member includes an internal opening for receiving the first end of the self-expanding device.
44. The system according to claim 36, further comprising a catheter into which said assembly and the self-expanding device can be positioned.
45. The system according to claim 36, wherein said flexible member comprises an elongate coil positioned about a portion of said elongate flexible member.
46. The system according to claim 36, wherein said elongate member includes a flexible guidewire that is rotatable relative to said introducer sheath and the self-expanding device.
47. The system according to claim 36, wherein said device retaining member includes a portion for protecting the first end of the self-expanding device.
48. The system according to claim 36, wherein the self-expanding device is a stent.
49. The system according to claim 36, wherein rotation of the protective coil results in movement of the first end away from the interior portion.
50. The system according to claim 36, wherein self-expanding device is a woven, porous stent.
Type: Application
Filed: Feb 29, 2012
Publication Date: Aug 30, 2012
Patent Grant number: 9095343
Applicant: TYCO HEALTHCARE GROUP LP (Mansfield, MA)
Inventors: Aaron Lee Berez (Menlo Park, CA), Quang Quoc Tran (Redwood City, CA)
Application Number: 13/407,835
International Classification: A61F 2/84 (20060101);